1.0.0.3 false Condensed Consolidated Balance Sheets (USD $) In Millions false 1 $ false false Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 $ false false Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 6 Current Assets 4 us-gaap_AssetsCurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 7 Cash and cash equivalents 5 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 882000000 882.0 false false 2 true true 789600000 789.6 false false No definition available. No authoritative reference available. false 8 Accounts receivable, net of allowance of $26.2 and $20.6 5 us-gaap_ReceivablesNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 488600000 488.6 false false 2 false true 482700000 482.7 false false No definition available. No authoritative reference available. false 9 Other 5 us-gaap_OtherAssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 166800000 166.8 false false 2 false true 128600000 128.6 false false No definition available. No authoritative reference available. true 10 Total current assets 5 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1537400000 1537.4 false false 2 false true 1400900000 1400.9 false false No definition available. No authoritative reference available. true 11 Noncurrent Assets 4 us-gaap_AssetsNoncurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 12 Property and equipment, at cost 5 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 5803900000 5803.9 false false 2 false true 5376300000 5376.3 false false No definition available. No authoritative reference available. false 13 Less accumulated depreciation 5 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1569700000 1569.7 false false 2 false true 1505000000 1505.0 false false No definition available. No authoritative reference available. true 14 Property and equipment, net 5 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 4234200000 4234.2 false false 2 false true 3871300000 3871.3 false false No definition available. No authoritative reference available. true 15 Goodwill 5 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 336200000 336.2 false false 2 false true 336200000 336.2 false false No definition available. No authoritative reference available. false 16 Long-term investments 5 us-gaap_OtherMarketableSecuritiesNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 61600000 61.6 false false 2 false true 64200000 64.2 false false No definition available. No authoritative reference available. false 17 Other assets, net 5 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 179600000 179.6 false false 2 false true 157500000 157.5 false false No definition available. No authoritative reference available. true 18 Total assets 4 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 6349000000 6349.0 false false 2 false true 5830100000 5830.1 false false No definition available. No authoritative reference available. true 21 Current Liabilities 5 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 22 Accounts payable 6 us-gaap_AccountsPayableCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 32800000 32.8 false false 2 false true 30000000 30.0 false false No definition available. No authoritative reference available. false 23 Accrued liabilities and other 6 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 405000000 405.0 false false 2 false true 380700000 380.7 false false No definition available. No authoritative reference available. false 24 Current maturities of long-term debt 6 us-gaap_LongTermDebtCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 17200000 17.2 false false 2 false true 17200000 17.2 false false No definition available. No authoritative reference available. true 25 Total current liabilities 6 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 455000000 455.0 false false 2 false true 427900000 427.9 false false No definition available. No authoritative reference available. true 26 Noncurrent Liabilities 5 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 27 Long-term debt 6 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 265700000 265.7 false false 2 false true 274300000 274.3 false false No definition available. No authoritative reference available. false 28 Deferred income taxes 6 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 356800000 356.8 false false 2 false true 340500000 340.5 false false No definition available. No authoritative reference available. false 29 Other liabilities 6 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 142900000 142.9 false false 2 false true 103800000 103.8 false false No definition available. No authoritative reference available. false 32 Ensco Stockholders' Equity 5 us-gaap_StockholdersEquityAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 33 Preferred stock, $1 par value, 20.0 shares authorized and none issued 6 us-gaap_PreferredStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 34 Common stock, $.10 par value, 250.0 shares authorized, 182.6 and 181.9 shares issued 6 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 18300000 18.3 false false 2 false true 18200000 18.2 false false No definition available. No authoritative reference available. false 35 Additional paid-in capital 6 us-gaap_AdditionalPaidInCapital us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 1781900000 1781.9 false false 2 false true 1761200000 1761.2 false false No definition available. No authoritative reference available. false 36 Retained earnings 6 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4527900000 4527.9 false false 2 false true 4114000000 4114.0 false false No definition available. No authoritative reference available. false 37 Accumulated other comprehensive loss 6 us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -3100000 -3.1 false false 2 false true -17000000 -17.0 false false No definition available. No authoritative reference available. false 38 Treasury stock, at cost, 40.2 and 40.1 shares 6 us-gaap_TreasuryStockValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true -1203500000 -1203.5 false false 2 false true -1199500000 -1199.5 false false No definition available. No authoritative reference available. true 39 Total Ensco stockholders' equity 6 us-gaap_StockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5121500000 5121.5 false false 2 false true 4676900000 4676.9 false false No definition available. No authoritative reference available. false 40 Noncontrolling interests 5 us-gaap_MinorityInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 7100000 7.1 false false 2 false true 6700000 6.7 false false No definition available. No authoritative reference available. true 41 Total equity 5 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5128600000 5128.6 false false 2 false true 4683600000 4683.6 false false No definition available. No authoritative reference available. true 42 Total liabilities and equity 4 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 6349000000 6349.0 false false 2 true true 5830100000 5830.1 false false No definition available. No authoritative reference available. true false 2 33 false HundredThousands UnKnown UnKnown false true